1. Field of the Invention
The invention relates to an area of intersection between a high-pressure chamber and a high-pressure duct.
2. Object and Summary of the Invention
To increase the strength in the area of intersection, it is possible to round the area of intersection.
It is the object of the invention to increase the high-pressure strength in the area of intersection between a high-pressure chamber and a high-pressure duct.
The object is attained, in an area of intersection between a high-pressure chamber and a high-pressure duct, in that the area of intersection includes at least one planar area or an area that is curved markedly less than the remaining area of intersection. The planar area may also be embodied as only nearly planar. The high-pressure chamber and the high-pressure duct are also called functional chambers. By means of the planar or nearly planar area, an intersection geometry is created, in which tensile stresses of the functional chambers that occur upon subjection to pressure are not superimposed directly and add up as they do in conventional intersection geometries. By means of the planar area in the area of intersection, it is attained that in the intersection geometry of the invention, under pressure, local pressure stresses or markedly reduced tensile stresses occur in an inner wall of the high-pressure chamber and are then superimposed with the tensile stresses in an inner wall of the high-pressure duct. Since with the intersection geometry of the invention, a tensile stress has only a reduced tensile stress or in the best case a pressure stress superimposed on it, the total is less and hence the maximum stress that occurs is reduced markedly.
A preferred exemplary embodiment of the area of intersection is characterized in that the high-pressure duct has a smaller diameter than the high-pressure chamber. The high-pressure chamber is preferably a chamber in an injector housing of a fuel injector that is filled with fuel at high pressure via a high-pressure inlet.
A further preferred exemplary embodiment of the area of intersection is characterized in that a cylindrical jacket face of the high-pressure chamber in the area of intersection has either the planar area or the area that is curved markedly less than the remaining area of intersection. In an essential aspect of the invention, the cross section of the high-pressure chamber is advantageously varied by removal of material, in such a way that a planar or nearly planar area is created.
A further preferred exemplary embodiment of the area of intersection is characterized in that the high-pressure duct in the planar area discharges into the high-pressure chamber. The exit from the high-pressure duct is shifted, in an essential aspect of the invention, into or to the planar or nearly planar area.
Further preferred exemplary embodiments of the area of intersection are characterized in that the area of transition between the planar area and the high-pressure chamber or the high-pressure duct is rounded. As a result, unwanted stresses can be reduced still further.
A further preferred exemplary embodiment of the area of intersection is characterized in that the planar area extends parallel to the longitudinal axis of the high-pressure chamber. Preferably, the planar area extends over a portion of the length of the high-pressure duct and then changes over into a cylindrical jacket face. The planar area may, however, also extend over the entire length of the high-pressure duct.
A further preferred exemplary embodiment of the area of intersection is characterized in that the high-pressure chamber, viewed in cross section, has two circular arcs, which on one end change over into the planar area. The circular arcs are preferably semicircles, which on their ends opposite the planar area are joined by means of a further planar or nearly planar area.
A further preferred exemplary embodiment of the area of intersection is characterized in that the high-pressure chamber, viewed in cross section, has two elliptical arcs, which on one end change over into the planar area. Preferably, the planar area is disposed parallel to the main axis of the ellipses to which the two elliptical arcs belong.
A further preferred exemplary embodiment of the area of intersection is characterized in that the high-pressure chamber, viewed in cross section, has two further planar areas, which are disposed perpendicular to the planar area from which they originate and change over into the cylindrical jacket face. The three planar areas form a U-shaped cross section with a base and two legs. The high-pressure duct discharges into the base. The two legs change over into the cylindrical jacket face, which in the area of intersection is reduced to a semicircular cross section.
Further advantages, characteristics and details of the invention will become apparent from the ensuing description, in which various exemplary embodiments are described in detail in conjunction with the drawings.